Motor panel voltmeter: require OCP?

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wallyswrld

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Our crane DC motor (208FLA) has a voltmeter tapped on the armature conductors just before they exit the panel (via conduit) to the motor. The voltmeter conductors (#16AWG) are <10feet long, remain entirely in the panel and are adequately sized to the meter load (which is in milliamps). The meter conductors are not fused. This exists on several cranes for at least 9 years w/o problems.

IMO, the meter conductors do not require OCP since they do not directly function/affect motor control (the conductors only feed the panel voltmeter mounted on the enclosure above the panel door for external viewing) and meet the 240.21(B)(1) criteria.

However, am being told the meter is still a motor control circuit requiring installation of a fuseholder/fuses. In addition, am told the fuseholder lineside conductors would have to be upsized to #8AWG per 430.72(A).

Anyone have a similar situation out there? Is the meter circuit a Feeder Tap [per 240.21(B)(1)] or a motor control circuit [per 430.72(A)]?
 
Its a motor control circuit, tapped. The size of the control conductors are determined by the BC-SC-GF device.
The simplest solution is a fuse, 16AWg is OK on a 10 amp.
 
Part VI of Art 430 is on Motor Control Circuits, the NEC clearly applies as a user can assemble a motor controller from listed parts available from a manufacturer.
 
Motor panel voltmeter: require OCP?

Thanks Tom & Larry. Guess my problem is with 430.72(A)'s first sentence "A motor control circuit tapped from the load side of a motor branch-circuit ... and functioning to control the motor(s) connected to that branch circuit shall be protected against overcurrent IAW 430.72."

The meter circuit does not function to control the motor at all. It could be removed and make no difference before/after how the motor operates. Its mounted above the panel door 30' behind the crane operator. Used only for curiosity/troubleshooting purposes. Was thinking motor control circuit only applies to things that can actually control the motor (ex: control speed/start/stop/etc) but not meters/indicators the operator can't see/use. Otherwise, was thinking 430.72(A) would not bother to state "and functioning to control the motor(s)".

Would prefer not having to take our cranes out of service for something that may not be required (which naturally makes me biased in interpreting 430.72(A)). Your comments/opinion are of course still welcome, even it it means more work for me ::smile:
 
Motor panel voltmeter: require OCP?

These are rather large gantry/portal shipyard cranes (about 60T lift). During crane construction (9-10 years ago) the contractor assembled the panels (& internal components such as these fateful meters) in the shop, then rigged the enclosures into position for final external hookup. More like a custom build enclosure thats been replicated several times to make a few cranes, yet, not really an off-the-shelf "manufactured control panel" package like they sell for current bridge cranes/etc.
 
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